Differences in pronunciation make speech difficult to understand. It doesn't matter whether persons involved are native or non-native. When you talk to a non-native speaker, do you change your /æɪ/ to /eɪ/ to make your speech easier to understand?
I have done, especially when I was in England, where I could reasonably guess what aspects of my accent were difficult to understand.
Of course, when a person needs do make themselves clear, they will pronounce "clothes" with all the sounds written. If they can.
Why? - if the proper pronunciation is 'close'? You seem to be asserting that 'clothes' is the correct form. All I'm saying is that 'clothes' is more easily understandable to mean 'clothes' than 'close' is.
But I don't understand how you can expect that non-native speakers utter difficult clusters in normal speech.
It's the same expectation that my German teacher had for me to say 'ich' and 'ach' properly. Of course, some non-native speakers will never get the hang of those sounds; and I will never say them consistently like a native German would. But I've always assumed that if you try to learn another language, you need to make an effort to use the sounds they use. Of course it's difficult. I don't think anyone here will claim that learning a foreign language is easy.
But I've already said that the OP could get away with 'munts' or 'munce'.
So, it depends on what you mean by "expect". I would expect everyone learning English to try to use the two /th/ sounds but, at the same time, I would also expect that not everyone will be able to do it.